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Newsletter #8
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News from the National Centers for
Innovation in Small Drinking Water Systems

Upcoming Events

A listing of webinars, symposia, and conferences relevant to this work.
Institute in Drinking Water Treatment
August 22-25 | Northampton, Massachusetts 
This course for engineers, scientists, utility personnel, and agency officials includes an extra one-day course on advanced treatment.  2017 Sustainable Water Management Conference
March 19-22 | New Orleans, Louisiana 
Submissions for technical sessions, workshops, and special topic sessions at this AWWA annual conference will be accepted until Thursday, June 30, 2016. 

Project Update from the WINSSS Center

The Water Innovation Network for Sustainable Small Systems (WINSSS) Center at the University of Massachusetts-Amherst is led by Dr. David Reckhow.
The WINSSS Center brings together a national team of experts to transform drinking water treatment for small water systems to meet the urgent need for state-of-the-art innovation, development, demonstration, and implementation of treatment, information, and process technologies in part by leveraging existing relationships with industry.
Real Time Detection of Nitrate Using Silver-Modified Screen-Printed Carbon Electrodes 
Rebecca Lai
University of Nebraska–Lincoln

Sensors ideal for use in small water systems should be user-friendly, cost-effective, sensitive, specific, and capable of real-time and continuous monitoring of the target analyte. While there are many new sensing technologies available for detection of nitrate, few can simultaneously fulfill these stringent requirements. Driven by this need, we have recently developed an electrochemical nitrate sensor that can potentially be used in small water systems (Fig. 1). The sensing mechanism is based on the electrocatalytic reduction of nitrate on a silver-modified paper electrode (Fig. 1C). The nitrate sensor was fabricated via electrodeposition of silver nanoparticles on a screen printed carbon electrode (Fig. 1D). Although the sensor was found to be functional in lab-generated samples, to ensure that it would work well with real-world samples, we tested the sensor with various nitrate-containing water samples provided by the Nebraska Public Health Environmental Lab. The sensor was capable of detecting nitrate in samples in which the matrix composition was not known (Fig. 1E). It is worth noting that the results presented here were obtained from three different sensors and on different days. The performance of the sensors was quite similar, as indicated by the small error bars. Furthermore, these results were obtained using a portable handheld potentiostat in conjunction with a custom-built electrochemical cell that can accommodate a sample volume as low as 10 µL (Fig. 1A and B). The detection was very fast; each scan required less than one minute. All these attributes suggest that this detection strategy could find application in real-time monitoring of nitrate.

 In the coming year, we plan to further characterize this sensor. Specifically, we will analyze the failure rate, and we hope to achieve a success rate of 97% (i.e., 97 out of 100 sensors should show the same response to the same nitrate sample). Next, we will analyze the reusability of the sensor; we would like to determine if the sensor can be reused over 150 times without showing signs of sensor degradation. We will also systematically evaluate the sensor’s response to potentially interfering species such as metal ions that can be deposited onto the sensor surface. Cost analysis is also part of the future work. We plan to use sensor strips with three active sensors so as to lower the cost per analysis (e.g., <$0.50 per analysis). Last, we will evaluate the shelf-life of the sensor if stored at room temperature in a sealed vacuum bag. These studies will enable us to estimate the marketability of this sensor device for use in small water systems and other agricultural analysis.
 

Project Update from the DeRISK Center

The Design of Risk-reducing, Innovative-implementable Small-system Knowledge (DeRISK) Center at the University of Colorado-Boulder is led by Dr. Scott Summers.
The DeRISK Center’s overall objectives focus on applying principles of risk reduction, sustainability and new implementation approaches to innovative technologies that will reduce the risk associated with key contaminant groups and increase the chance of adoption and sustainable use in small systems.
EPA Center Helping Small systems Manage Water Supplies Through Open Source Data Integration Tools

Sam Hatchett and Jim Uber, CitiLogics
Rob Janke and Michael Tryby, U.S. Environmental Protection Agency
Scott Summers and Chad Seidel, University of Colorado Boulder

The water industry has a case of data indigestion; we can’t stomach new investments in data technologies, because we’re still working on digesting SCADA, GIS, billing, maintenance, and regulatory data stores. This situation is stressful, because the world around us—including our customer base—is surrounded by tablets, smartphones, and cloud computing. While our customers are looking at real-time maps of weather, crime, or power outages, we are sending them annual CCRs through the mail; at some point, they won’t understand why we haven’t joined the party. Until that happens, the industry has a window of time to identify what data streams should be integrated and what technologies to adopt, based on a logical and practical consideration of the benefits.

While it’s impossible right now to prescribe an end-to-end set of data integration tools for the water industry, or even any one utility, part of the cure for data indigestion will be data integration standards — starting with efficient means of accessing various data stores using well established and open interface standards. The adoption of such standards, and development of useful software tools that embody them, has so far been outside the realm of industry workgroups, and even of the USEPA. It’s been seen as a problem that individual utilities should solve, and then share their solutions. But the rate of technological change that has resulted from such an evolutionary approach will fail to meet our customers’ expectations.

The EPA DeRisk Center believes that data integration is a valuable part of small system focused R&D, and started a prototype project to explore how existing technologies could be leveraged to start utilities down a productive path. The goal is user friendly software that provides simple, secure, read-only access to key operational data streams (e.g., those stored within a SCADA historian), with web-based dashboards for trending and alerting. Partnering with data analytics company CitiLogics, and the USEPA research laboratory in Cincinnati, a product called RTX:LINK was developed.

RTX:LINK has been piloted in the Milford, OH (population 6,000) water system, where it’s been providing 24 hour access to tank levels, pump statuses, and distribution system flows via mobile or desktop devices. LINK is initially configured with a setup wizard to establish database connections and select the data streams to archive. LINK then provides automatic and continuous transmission of SCADA data streams from the process historian to a modern, high-speed cloud database, and configures real-time dashboards for data visualization.

The team is actively working on high-value dashboard analytics that leverage the data hosted on the LINK platform, and has prototyped metrics that estimate the degree of mixing and turnover time in elevated storage tanks. Given that tank water quality impacts are important issues of concern to many utilities, RTX:LINK dashboards could give utility staff and management important new sources of information about how distribution system operations affect water quality. Real-time analytics for pump specific energy and disinfection CxT are in the works.

RTX:LINK is planned for distribution as a free open source product later in 2016. It is hoped that its development and distribution will help to bootstrap the adoption of data integration standards throughout the water industry.

Graduate Student Recognized for DeRISK Project

Natalie Hull, a PhD student at University of Colorado Boulder, earned second place in the International Ultraviolet Association's Best Student Paper Award contest for her work with Karl Linden on UV-LED disinfection. The award was given during the association's annual conference in February. 

Click here for more information about this DeRISK research project. 

Recent Publications

Evaluation of Ferrate as a Coagulant Aid/Oxidant Pretreatment for Mitigating Submerged Ultrafiltration Membrane Fouling in Drinking Water Treatment 

Yu, W., Yang, Y. and Graham, N. (2016). Evaluation of ferrate as a coagulat aid/oxidant pretreatment for mitigating submerged ultrafiltration membrane fouling in drinking water treatment. Chemical Engineering Journal, 298, 234-242. doi:10.1016/j.cej.2016.03.080.  

Why it's interesting: This study reveals that the application of potassium ferrate as a pre-treatment has strongly contrasting effects on ultrafiltration performance depending on whether it is dosed as a single chemical or in combination with FeCl3. Tests with FeCl3/K2 suggest that this combination results in the lowest viable bacteria and suspended solid concentrations in the membrane tank.  
Brine Disposal Options for Small Systems in California's Central Valley

Jensen, V., and Darby, J.L. (2016). Brine disposal options for small systems in California's Central Valley. Journal of the American Water Works Association, 108:5, 276-289. doi:10.5942/jawwa.2016.108.0045. 

Why it's interesting: An assessment of brine disposal options revealed that disposal costs represent up to 97 percent of the average total cost of tap water in the U.S., indicating that a regional approach to brine waste management is needed to bring small systems in the San Joaquin Valley into compliance.  
Assessment of Water Quality in Distribution Networks Through the Lens of Disinfection By-Product Rules

Islam, N., Sadiq, R., Rodriguez, M.J., and Legay, C. (2016). Assessment of water quality in distribution networks through the lens of disinfection by-product rules. Water SA, 42:2, 337-349. doi:10.4314/wsa.v42i2.17.   

Why it's interesting: This paper proposes and gives the results of the initial testing of an index to assess water quality in regards to compliance with DBP rules. The index makes use of flexible parameters to make it suitable for small communities with severe resource limitations. 

 

Industry News

Beneficial Biofilm Works as a 'Probiotic' to Control Biofouling 
Chemical engineers at Penn State have developed a biofilm with the ability to prevent biofouling of reverse osmosis membranes. 

Pesticides, Herbicides in Drinking Water Could Lead to Birth Defects 
A report out of Texas A&M shows that higher concentrations of nitrates, atrazine, and arsenic in private and public well water are linked to birth defects. 

EPA Sets New Level for Chemical PFOA in Drinking Water
As health departments in New York, Vermont, and New Hampshire grapple with the discover of elevated PFOA levels in public and private water supplies, the U.S. EPA announced a lifetime drinking water health advisory of 70 ppt. 

Senate Passes Energy and Water Appropriations Bill
The first major energy and water appropriation passed by the Senate in nearly a decade includes $1.275 billion for water supply projects and programs in the western U.S. 

Reacting to Flint Crisis, EPA Launches U.S. Drinking Water Study
The U.S. EPA has begun meeting with state officials, utility managers, and others to develop a national action plan on drinking water that will be released at the end of the year. 

In related news, Marc Edwards debunks pseudoscience presented by Hollywood actor and recognizes the DBP expertise of WINSSS director David Reckhow.  
The two National Centers for Innovation in Small Drinking Water Systems, based at the University of Colorado - Boulder and the University of Massachusetts - Amherst, are collaborative research groups charged with examining and reducing the barriers of innovative treatment technology implementation at small drinking water systems. The funding for the centers comes from the U.S. Environmental Protection Agency as part of its Science to Achieve Results (STAR) program.
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